This section provides background information related to the present disclosure which is not necessarily prior art.
Energy saving radial shaft seals are known to improve sealing performance by reducing friction between the seal lip and crankshaft through a reduction in radial load of 50% when compared to sprung rubber lip seals and 75% when compared to PTFE lip seals. Not only does the friction improvement reduce power consumption and improve fuel economy, it also reduces the amount of heat generated at the seal lip and crankshaft interface.
The Energy Saving Seal operates by pumping oil through a precision molded spiral interfacing with a rotating shaft which directs oil back into the engine or transmission. With the spiral pattern and its multiple points contacting the shaft, there is less risk associated with poor shaft conditions such as porosity or other imperfections, which are often the downfall of the sprung lip seal with its single point of contact with the shaft.
In some applications an energy saving seal needs to resist vacuum pressures that can cause the seal lip to lift off the shaft. According to the present disclosure, a seal is provided including a mounting portion having an outer diameter surface adapted to be received in a bore and a radially inwardly extending leg. An axially extending leg extends from an inner end of the radially inwardly extending leg. A hinge portion is disposed at an end of the axially extending leg, the hinge portion having a generally round cross-section with a larger diameter than said end of said axially extending leg where the hinge portion is attached. A main seal lip and a dust lip each extend from the hinge portion. The hinge portion allows the main lip and the dust lip to pivot while maintaining the angle between the main lip and dust lip, wherein during vacuum pressure, the hinge portion helps in making the dust lip engage the shaft faster thus producing a sealed contact if the main lip lifts off during the vacuum pressure.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.